Open AccessHigh-Quality (CH3NH3)3Bi2I9 Film-Based Solar Cells: Pushing Efficiency up to 1.64%
Author(s) -
Zheng Zhang,
Xiaowei Li,
Xiaohong Xia,
Zhuo Wang,
Zhegang Huang,
Binglong Lei,
Yun Gao
Publication year - 2017
Publication title -
the journal of physical chemistry letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.563
H-Index - 203
ISSN - 1948-7185
DOI - 10.1021/acs.jpclett.7b01952
Subject(s) - perovskite (structure) , energy conversion efficiency , quantum efficiency , bismuth , materials science , photovoltaic system , perovskite solar cell , optoelectronics , quantum dot solar cell , solar cell , polymer solar cell , chemistry , crystallography , ecology , metallurgy , biology
Bismuth-based solar cells have exhibited some advantages over lead perovskite solar cells for nontoxicity and superior stability, which are currently two main concerns in the photovoltaic community. As for the perovskite-related compound (CH 3 NH 3 ) 3 Bi 2 I 9 applied for solar cells, the conversion efficiency is severely restricted by the unsatisfactory photoactive film quality. Herein we report a novel two-step approach- high-vacuum BiI 3 deposition and low-vacuum homogeneous transformation of BiI 3 to (CH 3 NH 3 ) 3 Bi 2 I 9 -for highly compact, pinhole-free, large-grained films, which are characterized with absorption coefficient, trap density of states, and charge diffusion length comparable to those of some lead perovskite analogues. Accordingly, the solar cells have realized a record power conversion of efficiency of 1.64% and also a high external quantum efficiency approaching 60%. Our work demonstrates the potential of (CH 3 NH 3 ) 3 Bi 2 I 9 for highly efficient and long-term stable solar cells.